int main(void)
{
unsigned u;
for(u=0; u<65536; u++) {
unsigned s = u*u;
unsigned root = ff_sqrt(s);
unsigned root_m1 = ff_sqrt(s-1);
if (s && root != u) {
fprintf(stderr, "ff_sqrt failed at %u with %u\n", s, root);
return 1;
}
if (u && root_m1 != u - 1) {
fprintf(stderr, "ff_sqrt failed at %u with %u\n", s, root);
return 1;
}
}
return 0;
}
static av_cold void roq_dpcm_table_init(void)
{
int i;
/* Create a table of quick DPCM values */
for (i=0; i<MAX_DPCM; i++) {
int s= ff_sqrt(i);
int mid= s*s + s;
dpcmValues[i]= s + (i>mid);
}
}
void TquantTablesPageBase::writeMatrix(FILE *f,const char *section,const uint8_t *matrix,unsigned int len)
{
fprintf(f,"%s =\n",section);
int cnt=ff_sqrt(len);
for (int i=0; i<cnt; i++) {
for (int j=0; j<cnt; j++) {
fprintf(f,"%i%s",int(*matrix++),--len>0?",":"");
}
fprintf(f,"\n");
}
fprintf(f,"\n");
}
static unsigned char dpcm_predict(short *previous, short current)
{
int diff;
int negative;
int result;
int predicted;
diff = current - *previous;
negative = diff<0;
diff = FFABS(diff);
if (diff >= MAX_DPCM)
result = 127;
else {
result = ff_sqrt(diff);
result += diff > result*result+result;
}
/* See if this overflows */
retry:
diff = result*result;
if (negative)
diff = -diff;
predicted = *previous + diff;
/* If it overflows, back off a step */
if (predicted > 32767 || predicted < -32768) {
result--;
goto retry;
}
/* Add the sign bit */
result |= negative << 7; //if (negative) result |= 128;
*previous = predicted;
return result;
}
